Signal or alarm device for projecting machines



y 8 1 45. 'c. c. CLARK 2,375,197

SIGNAL 0R ALARM DEVICE FOR PROJECTING MACHINES Fiied Nov. 23, 1942 CHARLISSC, CLAfi/T Patented May 8, 1945 SIGNAL-ORi-ALARMiDEXl-IQE FOR. PROJECTING MAGHI'NES;

Charles C. Clark, Columbus,.0hio

Application. November 23, 1942;. Serial Jim.- 466585 sonims.

This invention relates to a signalor alarm. device for ready attachment to a, picture pro-- jecting machine for indicating to the operator when the film is nearly unwound and also-when it is about completely unwound from the film reel sothat there'may be no oversight and int'erruption in the continuity of the subject matter be ingshown whenthere' is=a change of fil'ms- A projection booth is-ordinarily equipped withtwo projectors to be run alternately in orderto avoid interruptions" for change offilms. film contains the start motor" and changeover cuesprinted thereon, the former being about twelve feet and the other beingabout two feet from the end-of thefilm. Signalsor' alarms are desirous to avoidhavingthe cues pass by unnoticed or not being timely observed by the-opera. tor; I

Heretofore the practice has been to provide a signal or alarm device attached to the magazine and cooperating with the reel forgiving a signal to the operator when a film is nearly unwound or is nearing completion. However, the alarm ismerely a temporary one, sucha 'ri'nging a bell; and, thus, if'th'e operator is not near the projector he-may' f an to hear the alarm. Moreover; an alarm or" signal which makesa loud noise is' obj actionable-inasmuchasit carr be heard by" those watching the showing of the picture; thereby distracting attention;

The aim of the present invention is to provide an alarm or signal which is given" for a-substantia'l period of time and is inaudible, or'substan tia-lly' so, and one which also gives a" warningalarm or signal at a predetermined time intervalbefore a final'signal or alarm is given. The-prelimina-ry or warningalarm" preferably continues at least until the final alarm is given so that'the operator may be alert to a change over the other projector. More specifically; there is provided a combination signal consisting of anelectric light which when turned onis accompanied by a slight clicking sound that is given at a predetermined time of one minute or morebefore the. end of the film, and another alarm device which" gives a final clickingsound five to eight seconds before theactual change over-from one projectiorr machine? to another. The electric light'continues on through the change over until the last used projection machine. has been retreaded with anotherfilm and made'ready for the continuation; of the feature subject.

Generally described, the invention comprises a device readily suitable for attachment to a magazine and provided with a plurality of relative'ly movable arms cooperating witlr the periplrcry of the'face of the film roll? to be independently released by the film at progressively timed intervals as the" film: is unwound to certain degrees nearing the end of therolli The armfl'rst 120 be released bythe film roll gives: a temporary or warning signal to put theoperator on the alert for a final alarm or signal which is givem when. the.- other' arm is: at a a. predetermined later intervali releasedlby'the fllm rc'llz Y 7 For a" better understanding ofi the invention, referencemay be: made to the; accompanying;

drawing, in: which Fig.1 1 is= a perspective vi'evwof-s a-film: magazine; with-a reel therein, of a. conventional picture prof-- jecti'on machine with an alarm or signal device embodying the invention attached theretotz'i Fig. 2 is an: enlarged top plan view of the de-- vice with partsof the magazine and filmroll brokenaway; and

Fig. 3'ziS- a view insideelevation ofi the d'evice: looking in the direction of' the arrow in Fig-z. 2t

Referring specifically to the drawing, in which like numerals are used to designate like parts; numeral l is a magazine ofa conventional pic-- ture projecting machine 2 provided on one side with an opening '5' through which an film ma 4 onthe reel 5 may be readily inserted and removedi. The opening-1s covered by alid or'door (not shown) fitting therein. I

At a convenient point on the magazine: the alarmor signal" device; generally described ass;

- may be attached by drillinga hole? through the closed wallof the magazine, whereby the device may be secured in position with the ends of arms- 8 and? 9' disposed to ride upon the upper portion of" the periphery of the filin roll; To avoid scratching of the film surface, the ends of arms." ii and 9 are provided with respective" rolls: Ill and l l mounted thereon for'rolling contact with the film. Arm e is madein sections l2 and- I2" telescoping together at joint [-31 A- screw F4 projects through the-end or section 1-2" and engages" washers- I 5 and I6 disposed onoppositesi'des-cf the section l'2"to becla-mped against the section t2 by tightening the screw. portion P6 is projectedfrom the-washer I B- beneath arm 9; thereby permitting the arm 8 to be-released independently'of arm 9'-but both to bereturned asagunitgto opera-tiveposition upon thefilm roll.

Arm- 9 is composedof sections I1 and I'8 telescoped togeth'er'at' joint Is: A- screw-1s" ifs fitted in' the wall ofsect-ion I'T adjacent thetelescoping' socket therein to impinge against the end of section I8 which is inserted within the socket. The

mit lengthening and shortening said arms to determine their release by the film rolls and also to regulate and determine the time intervals between the release of the difierent arms.

The extremity of section I2 may conveniently be bent at right angles to provide support for a clamp for attaching the device to the magazine. The clamp comprises a hollow tube 2| journaled on 20 having a collar 22 on one end provided with screw threaded portions from the collar 22 nearly to the opposite end. A nut 23 cooperates with the screw threaded portion to clamp the arm of a bracket 24 against the wall of the magazine,

said magazine wall being between the'bracket arm 24 and the collar 22. A lock washer 25 may advantageously be provided between the nut 23 and the bracket arm 24. The end of extremity:

20 is screw'threaded at 26 to receive a cap nut 21. tremity 2D ,to' receive arm 29 and cause it to be tightly secured in place between the cap nut 27 andthe bottom of slot 28.

Section "is advantageously provided with an extremity ll disposed at right angle and hollowed to provide a bore Ha whereby same may be. pivotally connected to the extremity 20 of the other arm. I

-; Bracket arm 24 is extended to support a holder device 30 for an electrical contact member 3|.

One wall 32, the one on which the contact member;3.l ismounted, is of insulating material, such as fiberboard or the like. Therest of the support may be of metal such as sheet metal stamped in s11itable;form.,to cooperate with the ,wall 32 for enclosing the contact member. There is a wall 32 opposite to 32, an end wall 33, and a back wall 34. A portion 33' of the end wall 33 is bent to providemeans for attaching, wall 32 in place by screws or bolts 35. Bolt 36 holds the electrical clip in place on wall 32 and is extending therethrough for reception of the end of a conducting wire 3'l leading to an electric light (not shown) which may be stationed at any desired, place. Bolts 36aproject through wall 32 and bracket arm 24. v Arm 23 is provided with a head 38 on the end opposite to that which is attached to extremity 20 and is;,,positione d to come into engagement with the contact member 31, when arm 8 is dropped orsreleasedby the film roll, and, completes the electrical circuit to light the lamp or actuate any suitable electrical signalling device.

A slot 28 is also provided in the end of ex- The, arm 8 is first released by the film roll to I light the signal lamp just before the film roll is completed.- When the film roll is completed or is about to be completed, arm 9 will then be released and drop upon the supporting portion l 6,. this causing a slight clicking sound which will warn the operator that the film roll has been completely shown and is to be replaced.

The device is attached to the magazine as above described with the ends of arms 8 and 9 riding upon theroll of film as same is being unwound from the reel. Arm 8 is of shorter length than arm '9, and will first be released when the film roll is unrolled sufficiently to be beyond its reach. It will drop and in turn cause the arm 29. to drop alsoand bring the part 38 in contact with the electrical contact for lighting the signal lamp or other electrical device. Droppin of the arm which turns on the light is accompanied by a slight clicking sound resulting from members striking together when coming in contact, and this gives an audible alarm to the operator. Dropping of the longer arm 9 at a later interval to strike against a member of the device also makes a slight clicking sound audible to the operator following the first warning alarm. The length of the arm is set in relation to film to drop at a desired time previous to the completion of the um'olling of the film roll. At a desired later time interval arm 9 will be released and will cause a slight click when dropped upon support 16'. Both arms may lift as a unit to operative position before a new film roll is inserted.

While the device has been shown in detail for the purpose of illustrating the invention, it will be understood that there maybe various changes in construction without departing from the spirit of the invention.

Iclaim:

1. An alarm or signal device for film rolls comprising a plurality of extensible arms pivoted to a supporting means, means attached to one of the arms and projecting beneath and adapted to be struck by the other arm, an electrical contact member, and circuit making and breaking member carried by one of the arms to cooperate with the contact member.

2. In combination with the magazine of a picture projector, a film roll and a signal device comprising a plurality of arms associated with the face of the film. roll for being independently and automatically released from association with the film roll to provide alarms at predetermined intervals near the completion of unwinding the film roll, the arm first released having an electrical contact, portion serving as a switch for a lighting signal and the arm next released adapted to strike against a member to cause an audible signal.

3.- A signal device comprising a plurality of arms of unequal lengths pivotally attached together by means on one arm having a hollow tube portion to journal an extension on the other arm to provide a pivotal connection, means for clamping the tube portion to support, and a signal device attached to each of the arms, said arms being provided with rollers disposed to contact the periphery of a supply roll and being independently and automatically released near the completion of unwinding the supply roll to give alarms at predetermined intervals.

4. A signal device comprising a plurality of arms of unequal lengths pivotally mounted upon a common axis and disposed to have free ends, each arm carrying a roller for providing rolling contact with the periphery of a supply roll at circumierentially spaced apart points, whereby said arms are automatically and independently released from contact with the roll at predetermined intervals near the completion of unwinding the roll, and means whereby said arms produce separate signals when so released from contact with the roll.

5. In combination with the magazine of a picture projector, a roll film and a signal device comprising a plurality of arms of unequal lengths in rolling contact with the face of the film roll, a common pivotv for the arms, two alarm means, means whereby the arm of shorter length operates one alarm and the arm of longer length operates the other alarm when the roll is unwound to near completion.

CHARLES CLCLARK. 

